Device for compressing corrugated tubes



April 5, 1932. F. J. sPRAGUE ET AL DEVICE FOR COMPRESSING CORRUGATED TUBES 3 Sheets-Sheet 1 Filed Sept. 5. 1930 LLI:

.LLFF Ll LLLLLLIIPVIILMLL INVENTORS ATTORNEYS.

April 5, 1932. F. J. SPRAGUE ET AL DEVICE FOR COMPRESSING CORRUGATED TUBES Filed Sept. 5, 1930 3 Sheets-Sheet 2 /aa j A T TOR/V15 YS.

April 5, 1932. F. J. sPRAGuE ET AL 1,852,487

DEVICE FOR COMPRESSING CORRUGATED TUBES ATTORNEYS.

Patented Apr.'` 5, 1932 UNITEDP STATES PATENT OFFICE I FRANK J'. SPRAG'UE AND MAX KNAB, OF NEW YORK, N. Y., .ASSIGINOIRSJ TO SPBAGUE SPECIALTIES COMPANY, OF QUINCY, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS DEVICE FOR COMPRESSING ('10RBfU'GA'lllElD` TUBES Application led September 5, 1930. Serial No. 479,976.

film-forming metal-as aluminum--to beused as anodes for electrolytic condensers and y if similar devices, and we shall describe our invention in connection with the manufacture of such tubes.

The dielectric capacity of a condenser of the electrolytic type is directly proportlonal l to the area of the anode. It is evidently of great advantage if a large anode area can be combined with a small volume, and therefore, it has been proposed in the copending appllcation of F. Desmond Sprague and R. U. Clark, Ser. No. 416,939, filed'December 27, 1929, to use for an anode a thin-walled tube of film-forming metal having corrugations 1n the form of a helical screw thread. Such an anode in addition to combining a large area with a small volume, has the advantage of a strong and rigid structure', relatively small ratio of edges to surface, can be constructed from a single piece of metal, and has other advantages fully described in the above referred to application.

A process to manufacture such tubes by providing a tube blank with relatively wide corrugations and subjecting such corrugated ..3 tube to a subsequent compressing process to close up the corrugations, has been described in a copending application of Max Knab, Ser. No. 441,128, iiled April 2, 1930.

The primary object of our present invention is to improve the apparatus for compressing such tubes, so as to simplify the operations, adapt them for mass production and to improve the quality of the product.

A further object of our invention is to provide novel means for the readjusting of the inside spacing of the corrugations after the compression of the tubes.

Further objects of our invention will appear as the description pro esses.

In the drawings, which orm part of this specification, Figure 1 is a top view of our improved compression ixture, showing it in an open position with a corrugated tube inserted therein before the tube is subjected to compresslon.

Fig. 2 is a. fractional top view of the lower half of the compression fixture with a corru ated and compressed tube inserted therein. 1g. 3 is a perspective view of the compressing apparatus comprising the compression fixture and the pressure-air operated compressing cylinder.

Fig. 4 is a. perspective view of one of the spacer-plates of the compression fixture.

Fig. 5 is a side elevation of a tool which serves to readjust the spacin of the corrugatlons within the tube after 1t has been compressed.

Fig. 6 is a top view of Fig. 5.

Fig. 7 is a front elevation-partly broken awayof another embodiment of a tool to readjust the inside spacing of the compressed tubes, showing the tool with the spacing pins retracted for the insertion of the tool 1n the tube.

Fig. 8 is a top view of Fig. 7.

Fig. 9 is a side view-partly broken awayof the tool of Fi 7 with the spacing pins proJecting as use for the spacing operation.

Fig. 10 is a top view of Fig. 9.

In the above referred to application of Max Knab, as has been stated, methods are described to provide a tube from a suitable blank with widely spaced helical corrugations or threads, to subsequently compress such corrugated tubes to a smaller pitch, whereby the final corrugatio'ns of the'tubes are flat and have substantially parallel faces.

The compression of the corrugated tubes in 'said application is accomplished in fixtures consisting of resiliently spaced flat plates assembled on and guided by suitable guide rods.

y block 42.

We have found that to obtain precise corrugations, it is desirable to have the active surface of the spacing plates conform to the shape which the corrugations are to assume after compression of the tube.

We have also provided for means which simplify and accelerate the compressing operation, give more uniform results, reduce expense and comply with all requirements of mass production.

In the above referred to application of Max Knab, there are also means provided-in the form of a resilient helix inserted in the tube during its compressionto prevent the possibility of closing-up the threads of the inside of the tube, when the threads are compressed to a very small pitch.

We have found that instead of providing means to prevent closing up of the threads inside of the tube during its compression, it is more expedient to subject the tube if required to a spacing operation after its compression whereby a suitable tool is inserted in the compressed tube which properly adjusts the openings between the corrugations inside the tube.

Referring now to Fig. 3, the compression device consists of a compression fixture A and a compression cylinder B, mounted on a common base 20.

The compression fixture proper (see Figs. 1 and 2) consists of a lower-half 30 and an upper-half 30 which are hinged together by means of hinges 31 allowing the upper-half to be swung open by means of a handle 32.

The tube 10 to be compressed, which is assumed to be an electrode for electrolytic condensers, is shown before compression in Fig. 1 and after compression in Fig. It consists of a tubular portion 11 provided with relatively widely spaced helical corrugations, and of a conical head 12 ending in a slightly' tapered stem 13 which is beveled at 14 and is provided lwith an extension l5 of smaller' diameter which is threaded at its end.

Each half consists of a U-shaped frame 1, having a base plate 2 and two side plates 3 3, which is provided on one end with a headblock 43 and on the other end with a stop The head-block is provided with depressions 44 and 45 conforming to t-he portions 12 and 13 of the tube.

The side plates 3 are provided with a folded edge 4 and with longitudinal plate guides 4l-41, which serve to guide loosely mounted spacing plates 60 inserted in the fixture. The spacing plates 60, as shown in Fig. 4. consist of fiat plates, the thickness of which corresponds substantially to the pitch to which the threads are to be compressed. The plates 60 are provided on both sides with guide recesses 61-61 and are undercut at 63-63, to

take care of the folded edge 4 of the side plates 3.

The forming portion of the spacing plates constitutes an annular rib 64 which is angularly disposed relative to the horizontal edges of the (plate 60, this angular disposition correspon ing to the helix angle of the thread of the compressed tube. On both sides of the rib 64, an annular recess is formed to provide a shoulder 66, the diameter of which is slightly in excess of the outside diameter of the tube 10. The inside diameter 67 of the rib 64 is slightly in excess of the root diameter of the tube. The plate 60 is also provided with two circular recesses 65-65 to receive coiled spacing springs 6 6 as shown in F ig. l, which properly space the plates 60 between the head-block 43 and the stop block 42.

We prefer to make the spacing springs 6 in the shape of conical coiled springs, fastened with their end of larger diameter to the plate 60 whereby when the tube 10 is compressed as will be later described, the springs 6 recede in the recesses 65.

To compress a tube, the fixture is opened, (see Fig. 1) and the corrugated tube l0 inserted preferably in the lower half, whereby its portions 12 and 13 come to rest in the corresponding depressions 44 and 45 ofthe headblock 43. At the same time, the threaded portion 11 of the tube comes to rest between and on the spacing plates 60, whereby the tube with its portions of smallest diameter falls in the apertures 67. The springs 6 provide for the proper distancing of the spacing plates 60.

To insure the spacing plates to assume an angular position corresponding to the helix angle of the tube before its compression, there is provided on one side of the head-block 43, a hole 47 in which is located a plunger 46. The plunger 46 is provided with a stem 46a surrounded by a spring 50 pressing against the plunger. The stem 46a projects from the hole 47 into a chamber 48 of the headblock 43 and is provided with a head piece 48a. The wall 49 separating the hole 47 from the chamber 48 constitutes a stop for the head piece 48a, thereby limiting the downward stroke of the plunger 46. In its extreme downward position the plunger 46. depresses one side of the spacing plates 60 to such an extent that they assume an angular position substantially corresponding with the helix angle of the tube thread of the non-compressed tube.

After the corrugated tube has been inserted in the lower half 30. the fixture is closed by folding over the top half 30. It should be understood that the top half is similar to the lower half in all respects and that its spacing plates, angularity of which is determined by a plunger 51 similar to plunger 46, conform to the upper half of the tube.

Closure of the fixture 30--30 is insured by 86, will remain in its extended position.

prevent the recoiling of the spacer plates 60.

a cover-lock 24 supported on a post 23 and actuated by a handle 25. y

For compression of the tube, we prefer to`use an air-pressure operated cylinder B, which is in fixed relation to the compression fixture A and consists of the cylinder proper 80, the two heads 81, which are secured to or form integral part with lugs 82-82 suitably fastened to the base plate 20. Located wi thin the cylinder 80 is a reciprocating piston 83 provided with-a piston rod 84, the free end of which projects through the cylinder 80 and carries a plunger 85. Pipes 89 and 90 respectively connect chambers 86 and 87 formed on the two sides of the piston to a three-wayk cock 88. The three-way cock 88 serves to connect either of the pipes 89 or 90, with pipe 91 supplying pressure air and connect at the same timethe other of the two pipes 89 or 90 to atmosphere. I

Compression of the tube 10 is accomplished by bringing the three-way cock 88 in a position (by a suitable handle not shown) so as to admit pressure air through the pipe 89 to chamber 86 and simultaneously connect pipe 90 and chamber 87 to atmosphere. This causes the piston 83 and the plunger 85 to move towards the fixture A. The plunger 85 which is in coaxial alinement with the fixture and the tube 10, thereby enters the fixture 30-30' and compresses the tube 10. It should be well understood that admission of the pressure through the three-way cock 88 is so regulated as to prevent too 'severeimpact on the fixture. 1

After the tube has been compressed, the compression fixture is opened by retracting the cover-lock 24 and lifting the upper half 30 by means of a handle 32. While for convenience of operation separate handles 32 and 33 are provided for the opening and closing of the fixture, it is evident that a single handle could be used. Upon opening of the up-` per-half, the compressed tube which assumes the shape shown in Fig. 2 will be found in either halfof the fixture. The lower spacing plates are retained in the position. to which they` were brought during compression by means of the plunger 85, which as long as air is admitted through pipe 89 to chambler of the upper-half under the force of the springs 6 after the opening of the fixture, we prefer to provide in the upper casing of the.

fixture a pair of pawls 39-39 which under the action of leaf-springs 38-38 are pressed through corresponding apertures of the wall of the casing 30. The pawls 39-39 are bevelled in the direction of the piston travel and do not interfere with Mthe compression of the tube, each successive -spacing plate, when pressed during compression against the pawls, forces them outwardly until the tube is fully compressed, when the pawls 39--39 catch on the last spacer plate.

After the compressed tube is removed from the fixture, the three-way cock 88 is' moved to slowly admit air via pipe 90 to chamber 87 and to exhaust pressure air from chamber 86 via pipe 89 to atmosphere. This causes the piston 83 and the plunger 85 to gradually move towards the right whereby the plates 60 under the action of the spacing springs 6 gradually return to their normal location.

To return to their original position the upper spacer plates 60--which are retained bythe pawls 39, there are provided cam levers 35-35 on the two sides of the upper casing 30 which cooperate with the springs 38-38. The cam levers 85are interconnected by a shaft 37 carried bybearings 36-36 secured to the top of the upper casings 30. A release handle 34 is attached to the front cam lever 35, manual operation of which causes both the front and the rear cam lever 35-35 to spread the pawl carrying springs 38-38 to press agains the pawls 39--39 thereby releasing them. Preferably when releasing the pawls 39 recoiling of the spacing plates is manually dampened.

lin case it is desire'd to compress a tube to very close corrugations and prevent thereby the possibility of the close-up of the threads inside of the tube, as well as to generally insure uniform clearances inside of the tube, it might be advisable to subject the tube after its compression toa subsequent spacing operation. For this purpose we employ a spacing tool which, as shown in Figs. 5 and 6, consists of a rod 100 forming on one end a socket 102 by means of which the tool can be mounted on a shaft of a motor and secured thereto by a set-screw 101.

A flat spiral spring 105 is secured to the cated on the inside diameter of the spring 105. The spring 105 is thus prevented from turning but is free to move along the axis of the rod. Three of the ends 104 ofthe ribs 103 are of equal length while the fourth 104 lies in the plane of a recess 109 formed at the free end of the rod and the spring 105 is secured by placing its bent end between the end 104' anpl the extension of the cam-shaped washer- 10 In practice, the spacing tool is rotated by a suitable motor and as the tube 10 is slipped over the fixture, the spring 105 progressively engages its threads thereby properly adjusting their inside spacing.

Instead of the spacing tool just described, another tool can be used for the same purpose, this being shownin Figs. 7 to 10. This tool consists of a rod 110 provided with a longitudinal cylindrical bore 111 which carries rotatably a rod 112. The rod 112 is rovided on one end with a sto pin 113 an on the other end with two at spacing lpins 114-114. Normally, the rod 112 is brought in the position as indicated in Figs. 7 and 8 whereby the tool can be slipped within the tube 10. T he rod 112 is now brought in the position shown in Figs. 9 and 10 whereby the pins lll-114 engage the Walls of the corrugation and guid l them to assume the proper distance as tbe tool is rotated relative to the tube lll. The proper position of the pins 114---111l is determined by the abutment ofthe pin ll against a. stop 113.

While we have described a specific apparatus to be used for the compression of corrugated tubes and the spacing of corrugations, and illustrated such in connection with tubes used for electrodes of electrolytic devices, it should be well understood that we do not wish to be limited to such description and illustration, but desire the appended claims to be construed as broadly as permissible in view of the prior art.

lVhat We claim as new and desire to secure by Letters Patent is:

1. A device for the compression of corrugated tubes comprising a casing, a series of spacing plates therein, said plates having ribs adapted to embrace the root of a tube being compressed. the ribs being disposed at angles to the plate corresponding to the helix angle of the thread of the tube.

2. A device for the compression of corrugated tubes comprising a casing, a series of spacing plates therein, said plates having ribs adapted to embrace the root of a tube being compressed, the ribs being disposed at angles to the plates and being of inside diameter slightly in excess of the root diameter of the tube.

3. A device for the compression of corrugated tubes comprising a casing, a series of spacing plates therein, said plates having ribs` adapted to embrace the root of a tube being compressed, the ribs being disposed at angles to the plates, the plates being provided with shoulders which in diameter are slightly in excess of the outside diameter of the tube;

4. A device for the compression of corrugated tubes comprising a series of spacing plates, said plates having ribs arranged at angles to the plate, and provided adjacent their outer periphery with shoulders, the inside diameter of the ribs being slightly in excess of the root diameter of the tube, and the diameter of the shoulders being slightly in excess of the outside diameter of the tube.

5. A device for the compression of corrugated tubes comprising a casing, a series of spacing plates therein adapted to be moved substantially into abutting relation when compressing a tube, the plates being provided with opposing recesses for receiving the opposite sides of the corrugations of the tube and being provided with ribs angularly disposed with reference to the plates and adapted to engage between the corrugations of the tubes.

G. A device for the compression of corrugated tubes comprising a casing, a series of spacing plates therein adapted to be moved substantially into abutting relation when compressing a tube, the plates being provided with opposing recesses for receiving the opposite sides of the corrugations of the tube and being provided with rubs angularly disposed with reference to the plates adapted to engage between the corrugations of the tubes, and means to normally hold the spacing plates in an angular position which corresponds to the helix angle of the tube to be compressed.

7 In a device for the compression of corrugated tubes, the combination of a series of spacing plates having ribs arranged adapted to embrace the root of a tube being compressed and corresponding in angle to the helix angle of the thread of the tube, and a fluid-actuated plunger adapted to shift the plates for compressing the tube.

8. In a device for the compression of corrugated tubes comprising a casing, spacing plates and resilient means to normally hold apart said plates, a plunger to shift the plates and compress the tube, and means to retain the spacer plates in their shifted position against the pressure of the resilient means after the pressure exerted by the plunger is relieved.

9. A device for the compression of corrugated tubes, comprising a series of spacing plates having ribs adapted to embrace the root of the tube being compressed, a spring connected to each plate to normall hold it apart from the adjoining plate, an a recess in the spacer plate into which the spring recedes when t a plates are shifted for the compression of the tube.

10. A device for the spacing of the corrugations of a tube after its compression, comprising a rotatable shaft and a selfalining spring having substantially a profile and pitch corresponding to the opening between the corrugations of the tube, said spring adapted to thread the corrugated tube.

11. A device for the proper inside spacing of corrugated tubes comprising a shaft, and a member pivoted with respect to the shaft, said member carrying on one end means for forcing the wall of the corrugations to assume predetermined distances apart, and means on its other end for shifting the member with reference to the shaft.

12. A device for the inside spacing of the corrugations of a tube comprising a shaft. a rod rotatable with reference thereto, the rod being 'provided with means for engaging the corrugations of the tube and with means for shifting the rod with reference to the shaft.

13. A tool for the spacing of the corrugations of a tube after its compression, comprising a rotatable shaft adapted to be inserted Within said tube, said shaft carrying a self-alining spring having a profile and pitch substantially corresponding to the opening between the corrugations of the tube, said spring adapted to thread the corrugated tube.

' FRANK J. SPRAGUE.

l5 MAX KNAB. 

